In the last decade, the rates of opioid misuse and entry in substance abuse treatment for opioid dependence have increased significantly. An increasing number of opioid dependent individuals are being treated with buprenorphine (an effective, safe, more convenient, accessible alternative to methadone treatment). After a period of maintenance for patients, the majority of opioid dependent patients are interested in coming off the medication, either out of personal preference (e.g., do not want to substitute on addiction for another) or necessity (e.g., cannot afford it). Buprenorphine discontinuation, even when planned as a dosing taper, is often associated with opiate withdrawal and many patients express concern about the anticipated withdrawal symptoms; in turn, many experience decreased self-efficacy to remain abstinent during the process. There is a lack of available treatment resources to help patients manage buprenorphine discontinuation effectively. Therefore, we propose to harness the advantages afforded by existing technologies to address this important, unmet treatment need. We propose to develop a smartphone application (called OFFBup) that will help patients manage withdrawal during buprenorphine taper and detoxification. The components of the OFFBup application will be consistent with Relapse Prevention Theory (e.g., coping with withdrawal, increasing self-efficacy) and operationalized following the tenets of Self-Determination Theory (i.e., competence, autonomy, and relatedness). After the development of the OFFBup application, we will conduct a small RCT of 50 opioid dependent patients undergoing buprenorphine discontinuation to determine the feasibility and preliminary efficacy of the OFFBup application. The OFFBup smartphone intervention will be a resource where patients can access (anytime and anywhere) educational information, emotional and instrumental support, and that permits self-monitoring with accompanying feedback. If the OFFBup application were to be effective in helping patients undergoing buprenorphine detoxification by decreasing relapse to illicit drug use, it could be integrated into the standard of care of office-based buprenorphine clinical practices, as well as methadone programs, thereby having a substantial public health impact.